Currently, Al—Ti—B alloy is much popularly employing in Al material machining as a most efficient preliminary alloy for Al and Al alloy coagulation crystal grain refinement. A refinement ability of the Al—Ti—B alloy crystal grain is a very important factor when judging a quality of Al processing material. Usually, the better the Al—Ti—B alloy crystal grain refinement ability is, the higher yield strength and the better malleability of the Al material are. Therefore, the Al—Ti—B alloy manufacturers and research organizations are forward into developing improvements of the Al—Ti—B alloy crystal grain refinement ability. The US aluminum association has specially ruled an AA value to represent the crystal grain refinement ability. The AA value is a value that can be used for measuring the Al—Ti—B alloy crystal grain refinement ability, and the lesser the AA value is, the better the refinement ability of the Al—Ti—B alloy is. That is, the lesser AA value that the Al—Ti—B alloy added during Al and Al alloy producing process has, the more refined the crystal grain of the Al and Al alloy are. With a development of the process and refinement technology, the AA value is decreased from 250 at very beginning to 170. Presently, alloy fabrication technology is focused on material components, melting process, and such like. However, a quality control during a press process of the Al—Ti—B alloy has been ignored or indifferent to people. The press process includes mill rolling and cast extrusion machine extruding, and many believe that a ratio of the sectional area before press process to that after press process (defined as compression ratio), a variation of temperatures before and after press process, a line speed at exit, and a quantity of the standers have relations with the refinement ability of the Al—Ti—B alloy crystal grain, and there is no quantitative optimal control method for control the refinement ability of the Al—Ti—B alloy crystal grain through these respects including compression ratio.
What is needed, therefore, is a method for controlling variations of Al—Ti—B alloy crystal grain refinement ability through controlling a compression ratio of sectional area of Al—Ti—B alloy that can overcome the above-described deficiencies.